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Figure 12.5. Annualized rates of stand-level basal-area growth, basal-area mortality, stem recruitment, and stem mortality over consecutive census intervals for plots grouped into "slower growing less-dynamic" (a) and "faster growing more-dynamic" (b) forests. Of the slower-dynamics group, 20 of 24 plots are from eastern and central Amazonia, whereas just two are from western Amazonia. Of the faster-dynamics group, 24 of 26 plots are from western Amazonia, with just one from central Amazonia. The remaining three plots are from Venezuela and outside the Amazon drainage basin. Changes have occurred across the South American continent, and in both slower- and faster-dynamic forests (from Lewis et al., 2004b).

Finally, a recent paper from a cluster of plots in central Amazonia has shown consistent changes in tree species composition over the past two decades (Laurance et al., 2004). Many faster-growing genera of canopy and emergent stature trees increased in basal area or density, whereas some slower-growing genera of sub-canopy or understory trees decreased in density. Laurance et al. (2004) provide evidence of pervasive changes in central Amazonian forests: growth, mortality, and recruitment all increased significantly over two decades (basal area also increased, but not significantly so), with faster-growing genera showing much larger absolute and relative increases in growth, relative to slower-growing genera. Further studies are urgently needed to determine whether comparably large shifts in tree communities are occurring throughout the tropics.

Figure 12.6. Five-year running means (solid line) with 95% confidence intervals (dashed lines) of liana stem density per hectare (>10-cm diameter at breast height), with values plotted separately for northern Peru (filled squares), southern Peru (filled triangles), Bolivia (filled circle), and Ecuador (unfilled squares) (adapted from Phillips et al, 2002b; see that paper for full details of field and analytical methodology).

Figure 12.6. Five-year running means (solid line) with 95% confidence intervals (dashed lines) of liana stem density per hectare (>10-cm diameter at breast height), with values plotted separately for northern Peru (filled squares), southern Peru (filled triangles), Bolivia (filled circle), and Ecuador (unfilled squares) (adapted from Phillips et al, 2002b; see that paper for full details of field and analytical methodology).

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